Many heat dissipating systems utilize a heat pipe attached to a radiator wherefrom heat is radiated into the environment. Fluid contained in the heat pipe is vaporized at the hot end, wherefrom it is transposted to the cooler end by the pressure differential between the two ends. At the cooler end the heat pipe is attached to the radiator whereat the vapor is condensed and caused to flow back to the hot end by capillary means disposed within the container. Deterioration of the radiator with time severely limits the efficiency of the system and replacement is required since the radiator is permanently attached to the heat pipe for maximum heat transfer, it is not a replaceable unit. Consequently, for space applications the entire heat pipe-radiator assembly must be replaced on orbit. Incorporation of heat exchanger surfaces, in unbonded contact, in the heat transport path from the fluid loop to the radiator is a necessary condition for disconnect capability of plug-in replaceability of the heat pipe/radiator assembly.
One replaceable heat pipe-radiator assembly in the prior art has the hot end of the heat pipe embedded in a rectangular heat conducting block which transfers heat by contact conductance to a flat plate of dimensions greater than the block. The block extends from one side and is bolted to another flat plate wherein pipes of cooling fluid are embedded which extend into the heated area to be cooled. This device, though providing a replaceable heat pipe-radiator assembly, does not provide the heat exchange efficiency between the two flat plates that is required in many applications. Additionally, this arrangement has the added complication of bolt removement and replacement when an exchange is to be made. A more efficient variant of this system bolts flat plates containing cooling fluid pipes to two surfaces of the rectangle. Though this provides more efficient heat transfer, the undesirable complication of bolt removal and replacement for an exchange of assemblies remains.
A heat exchange that exhibits improve heat transfer over the flat plate configuration utilizes a cylindrical sleeve positioned over the hot end of the heat exchanger. The inner surface of the sleeve, that surface facing the heat pipe, has an inflatable bladder containing the coolant fluid. In this device, the bladder is expanded to maintain thermal contact with the heat pipe by pressurizing a gas containing chamber in the bladder. Although the device provides more efficient heat transfer to the heat pipe than does the flat plate devices, it is bulky, requires a gas supply, and becomes inoperative should a puncture occur in the bladder. Yet another device is described in U.S. Pat. No. 4,324,375 entitled "Heat Sink Fluid-to-Fluid Mechanical Coupling of Spacecraft Coolant Systems". The disadvantages of U.S. Pat. No. 4,324,375 are the same as those previously mentioned for the bladder.
An object of this invention is to provide contact heat exchanger surfaces and supporting infra structures to meet or exceed the stringent requirements of space station type applications.